Machine Readable Entity ID

/* Machine-Readable Entity ID Bookmarklet */
/*
    Welcome! Thanks for checking this out. This JavaScript bookmarklet will help you easily find the MREID (when available) on a Google SERP. Questions can be left as comments at: https://www.upbuild.io/blog/machine-readable-entity-ids-seo/
*/

// First, try to grab the DOM  element that contains the MREID. NOTE: This _will_ break when/if Google changes the markup of their SERPs.
var knowledgeNode = document.querySelector("#rhs .kno-ftr > .kno-fb > div[data-async-context]");
// Second, check that something was actually found above. If we try this on a null variable, we'll have issues so we need to avoid doing that.
if (knowledgeNode !== null) {
    // A. cardID will be equal to a cleaned up MREID.
    var cardId = unescape(document.querySelector("#rhs .kno-ftr > .kno-fb > div[data-async-context]").getAttribute("data-async-context").split("card_id:")[1].split(";")[0]);
    // B. Print a success message to the console.
    console.log("%cSuccess! An MREID was found!","color: green; font-size: large");
    console.log("The machine-readable entity ID for\nthis search entitiy is " + cardId);
    // C. Print a success message to the SERP itself. So meta!
    var node = document.createElement("strong");
    var text = document.createTextNode("MREID is " + cardId + " | ");
    node.appendChild(text);
    var link = document.createElement("a");
    link.setAttribute("href","https://trends.google.com/trends/explore?q=" + cardId);
    link.setAttribute("target","_blank");
    link.setAttribute("rel","noopener");
    var linkText = document.createTextNode("Check via Google Trends");
    link.appendChild(linkText);

    // D. Worth noting, we finde the element where Google reports "About X results" and append our message to that.
    //document.getElementById("resultStats").appendChild(node);
    document.querySelector("#kxbcct,#resultStats").appendChild(node);
    document.querySelector("#kxbcct,#resultStats").appendChild(link);
}
// Third (AKA, fallback "Second"), we do something if no MREID was found on the SERP.
else if (knowledgeNode == null) {
    // See B above.
    console.log("%cSorry! No MREID found!","color: red; font-size: large");
    console.log("No machine-readable entity ID was found on this page. This is likely not an entity Google recognizes.");
    // See C above.
    var node = document.createElement("strong");
    var text = document.createTextNode("No MREID found");
    node.appendChild(text);
    // See D above.
    document.getElementById("resultStats").appendChild(node);
}